Take a felt square and cut out two small squares at either side in the middle.
Fold over an edge at the side of the square so that it lays flat below the inner line of the square.
Fold over the over edge and pin in place.
Turn the now pyramid shaped felt upside down and pin along the open edge.
Repeat the previous steps with the other side and square hole. Push the shape out and it should stand up on it's own.
Take a needle and thread and sew along the edges of the box.
Decorate with buttons, beads, sequins or felt shapes.
Fill with useful things and get organised.